California Code, Government Code - GOV § 70354

The components of the county facilities payment are based on the actual annual direct and indirect county expenditures on court facilities. In the case of a shared use building, the amounts are prorated for the court's usable space in the building as a percentage of total usable space in the building. The determination of the court's usable space and the total usable space shall be made by the standard methodology used for determining usable space by the Department of General Services.